【作者】 王凯建； 丁国良； 姜未汀；

【Author】 WANG Kaijian, DING Guoliang, JIANG Weiting (Institute of Refrigeration and Cryogenics , Shanghai Jiao Tong University , Shanghai 200030, China)

【机构】 上海交通大学制冷与低温工程研究所；

【摘要】 纳米尺度传热流动显示的结果表明,纯化合物制冷工质和有纳米颗粒混合的制冷工质在发生蒸发相变传热时具有明显不同的热流动特性。在有纳米颗粒混合的制冷工质中,液体受热汽化时在传热面附近出现大量的微小气泡,其尺寸和纯化合物制冷工质蒸发相变传热时出现的气泡相比,小一个数量级以上,密度高、移动速度快。根据流动显示的结果,分析了多孔质层、热输运以及边界层厚度减小等支配纳米尺度传热主要因子的影响。更多还原

【Abstract】 The results of fluid visualization on nano-scale heat transfer show that, there are clearly different characteristic features of thermal and fluid flows, for the pure refrigerant and the refrigerant mixed with the nano-size particles, when the evaporation phase change occured. When the refrigerant mixed with the nano-size particles is heated, a mount of micro-size bubbles appear on the heat transfer surface. Compared with that of the pure refrigerant, the bubbles size in the refrigerant mixed with the nano-size particle is one order of magnitude smaller, the flux is higher and the moving speed is faster. The main factors which dominate the nano-scale heat transfer, nano-particle porous layer, heat transfer and reduction of the boundary layer, are also analyzed with the results of fluid visualization.更多还原